The present invention relates to integrated circuits in general, and more particularly, to an analog signal processing circuit including an analog signal multiplexing circuit and a ranging circuit in cascade therewith adapted for use in an integrated circuit.
Electronic measurement and control products having application in industrial and utility environments are presently utilizing programmed microprocessor systems which offer increased product performance. However, these systems are not without their drawbacks. For example, most microprocessor systems require analog signal processing circuitry including an analog-to-digital converter and analog signal multiplexing and ranging circuitry for use therewith. In addition, the microprocessor requires supervision circuitry for performing the commonly known functions of "power-on/down" reset and "deadman" reset for use in conjunction with the execution of the microprocessor's programmed instructions. And, all such electronic products require power supply regulation and generation circuitry. Accordingly, the cost and complexity of the aforementioned ancillary circuits tend to negate the increased performance offered by the programmed microprocessor systems.
It has become a challenge to circuit designers to find innovative methods to significantly reduce the cost and complexity of these ancillary circuits in order to render a more viable microprocessor system. One such method is being proposed herein for combining these necessary ancillary circuits into a single custom linear integrated circuit for a wide span of microprocessor system applications. Having the ancillary circuits embodied in a single integrated circuit has the affect of increasing reliability and, as the frequency of use and manufacturing volume developes, of eventually reducing costs.